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<div class="section" id="void">
<h1><a class="toc-backref" href="./data-types-miscellaneous.html#id1585">void_</a></h1>
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<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
<pre class="literal-block">
struct <a href="./void.html" class="identifier">void_</a>
{
    typedef <a href="./void.html" class="identifier">void_</a> type;
};

template&lt; typename T &gt; struct is_void;
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<h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
<p><tt class="literal"><span class="pre"><a href="./void.html" class="identifier">void_</a></span></tt> is a generic type placeholder representing &quot;nothing&quot;.</p>
<!-- In many cases, returning ``void_`` from a metafunction to signal
an absence of the requested data leads to a simpler user code than
having a separate metafunction specifically for the purpose of
performing the corresponding check. -->
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<pre class="literal-block">
#include &lt;<a href="../../../../boost/mpl/void.hpp" class="header">boost/mpl/void.hpp</a>&gt;
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<p><a class="reference internal" href="./data-types.html">Data Types</a>, <a class="reference internal" href="./pair.html">pair</a>, <a class="reference internal" href="./empty-base.html">empty_base</a>, <a class="reference internal" href="./bool.html">bool_</a>, <a class="reference internal" href="./int.html">int_</a>, <a class="reference internal" href="./integral-c.html">integral_c</a></p>
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